List of highly toxic gases

Many gases have toxic properties, which are often assessed using the LC50 (median lethal concentration) measure. In the United States, many of these gases have been assigned an NFPA 704 health rating of 4 (may be fatal) or 3 (may cause serious or permanent injury), and/or exposure limits (TLV, TWA/PEL, STEL, or REL) determined by the ACGIH professional association. Some, but by no means all, toxic gases are detectable by odor, which can serve as a warning. Among the best known toxic gases are carbon monoxide, chlorine, nitrogen dioxide and phosgene.

Definitions Toxic: a chemical that has a median lethal concentration (LC50) in air of more than 200 parts per million (ppm) but not more than 2,000 parts per million by volume of gas or vapor, or more than 2 milligrams per liter but not more than 20 milligrams per liter of mist, fume or dust, when administered by continuous inhalation for 1 hour (or less if death occurs within 1 hour) to albino rats weighing between 200 and 300 grams each. Highly Toxic: a gas that has a LC50 in air of 200 ppm or less. NFPA 704: Materials that, under emergency conditions, can cause serious or permanent injury are given a Health Hazard rating of 3. Their acute inhalation toxicity corresponds to those vapors or gases having LC50 values greater than 1,000 ppm but less than or equal to 3,000 ppm. Materials that, under emergency conditions, can be lethal are given a Health Hazard rating of 4. Their acute inhalation toxicity corresponds to those vapors or gases having LC50 values less than or equal to 1,000 ppm.

List Chemical nameChemicalformulaCAS numberNIOSHIDLH(ppm)OSHA PEL / NIOSH REL / ACGIH TLVNFPA 704 RatingsLC50 (ppm)Odor threshold (ppm)HealthSpecialHazardAmmoniaNH37664-41-73003COR4230 (mouse, 1 hr)Arsenic pentafluorideAsF57784-36-35 4ArsineAsH37784-42-134Bis(trifluoromethyl)peroxideC2F6O2927-84-410Boron tribromideBBr310294-33-4503WBoron trichlorideBCl310294-34-5254WBoron trifluorideBF37637-07-225OSHA, ACGIH (1962) 1 ppm ceiling4BromineBr27726-95-633OX<0.01Bromine chlorideBrCl13863-41-71500 (TQ)3OXBromomethaneCH3Br74-83-9250NIOSH PEL 20 ppm3Methyl bromide - OECD HPVMETHYL BROMIDE CAS N°: 74-83-9Carbon monoxideCO630-08-01,200(moderatelytoxic)3ChlorineCl27782-50-510ACGIH (1986) STEL-TLV 1 ppm3OX1Chlorine pentafluorideClF513637-63-3Chlorine trifluorideClF37790-91-212ACGIH (1979) Ceiling limit 0.1 ppm4W+OXInadequate odorChloropicrinDecomposes in gaseous form.CCl3NO276-06-22ACGIH (1990) TWA-TLV 0.1 ppm4CyanogenC2N2460-19-5ACGIH (1966) TWA-TLV 10 ppm4Cyanogen chlorideCNCl506-77-4ACGIH (1977) ceiling limit 0.3 ppm4DiazomethaneCH2N2334-88-32ACGIH (1970) TWA-TLV 0.2 ppm4DiboraneB2H619287-45-715ACGIH (1990) TWA-TLV 0.1 ppm4WInadequate odorDichloroacetyleneExplodes in gaseous form.C2Cl27572-29-4NIOSH REL 0.1 ppm CeilingDichlorosilaneH2Cl2Si4109-96-02500 (TQ)4 W1785-2092DimethylmercuryHgC2H6593-74-84Ethylene oxide (anhydrous)C2H4O75-21-8800REL TWA <0.1 ppm, 5 ppm Ceiling3FluorineF27782-41-4ACGIH (1970) STEL-TLV 2 ppm4OX20 ppbFormaldehyde (anhydrous)CH2O50-00-020NIOSH REL 0.016 ppm, Ceiling limit 0.1 ppm3GermaneGeH47782-65-2NIOSH REL 0.2 ppm4Hydrogen azideHN37782-79-8NIOSH REL: 0.1 ppm Ceiling4Hydrogen cyanideHCN74-90-8504Hydrogen fluorideHF7664-39-3304POIHydrogen selenideH2Se7783-07-51ACGIH (1990) TWA-TLV 0.05 ppm4Hydrogen sulfideH2S7783-06-410040.3Hydrogen tellurideH2Te7783-09-74Nickel tetracarbonylNi(CO)413463-39-3249.642Nitrogen dioxideNO210102-44-0133OX4Osmium tetroxideOsO420816-12-00.0013OX0.0019Oxygen difluorideOF27783-41-70.54OX0.5Perchloryl fluorideClFO37616-94-61003OXPerfluoroisobutyleneC4F8382-21-81.2 ppmPhosgeneCCl2O75-44-524PhosphinePH37803-51-2504Phosphorus pentafluoridePF57647-19-025TLV - TWA 0.25 ppm ACGIH & OSHA4Selenium hexafluorideSeF67783-79-12OSHA PEL, NIOSH REL, ACGIH (1992) TWA-TLV 0.05 ppm3Silicon tetrachlorideSiCl410026-04-73WSilicon tetrafluorideSiF47783-61-13WStibineH3Sb7803-52-35OSHA PEL/NIOSH REL/ACGIH TLV: 0.1 ppm4Disulfur decafluorideS2F105714-22-71ACGIH (1962) ceiling limit 0.01 ppm4OXSulfur tetrafluorideSF47783-60-0OSHA PEL/NIOSH REL/ACGIH (1992) ceiling limit 0.1 ppm3WTellurium hexafluorideTeF67783-80-41 NIOSH REL/ACGIH (1992) TWA-TLV 0.02 ppmTetraethyl pyrophosphateC8H20O7P2107-49-35ACGIH (2006) TWA-TLV 0.01 mg/m34SulfotepC8H20O5P2S23689-24-510NIOSH PEL TWA 0.2 ppm4Trifluoroacetyl chlorideC2ClF3O354-32-5 Tungsten hexafluorideWF67783-82-63W

See also List of Schedule 1 substances (CWC) EPA list of extremely hazardous substances Chemical warfare Chemical weapon List of chemical warfare agents List of psychoactive drugs used by militaries Psychochemical warfare List of gases Toxicity class Toxicity label

Notes

References

External links

OSHA Limits for Air Contaminants OSHA Permissible Exposure Limits California Department of Industrial Relations Permissible Exposure Limits for Chemicals